Tribonacci numbers: a(n) = a(n-1) + a(n-2) + a(n-3) with a(0)=0, a(1)=1, a(2)=0.

Terms

a(0) =0a(1) =1a(2) =0a(3) =1a(4) =2a(5) =3a(6) =6a(7) =11a(8) =20a(9) =37a(10) =68a(11) =125a(12) =230a(13) =423a(14) =778a(15) =1431a(16) =2632a(17) =4841a(18) =8904a(19) =16377a(20) =30122a(21) =55403a(22) =101902a(23) =187427a(24) =344732a(25) =634061a(26) =1166220a(27) =2145013a(28) =3945294a(29) =7256527